| A | B |
|---|
| igneous rock | rock formed by the hardening of hot, molten magma |
| metamorphic rock | rock formed by exposing igneous or sedimentary rock to extremem heat and pressure |
| sedimentary rock | rock formed when sediment is compacted |
| clay | stiff, sticky, fine-grained soil |
| erosion | the wearing away of rock or soil by wind, water, or ice |
| pebble | a small, smooth stone |
| rock | a very hard material made of minerals |
| geology | the study of rocks, soil, and minerals |
| boulder | a large rock |
| dust | a dry powder made of tiny pieces of rocks and soil |
| compress | to squeeze tightly together |
| mineral | a solid natural material; not from a plant or animal |
